I just finished the stripboard version of the WSG. When I power it up it works perfectly for about 1 minute (wow this thing sounds awesome) then it slowly dies out into silence. All the knobs work just fine (even the filter) when it is powered on for that brief moment. I used a fresh battery and I've also tried a godlyke power supply that gives a steady "9v." The results occur if I use a HCF40106 as well as a CD40106. Any help would be great.

Well, after some troubleshooting, I removed the 100uF capacitor at C7 and just jumpered between the two places. Now the WSG works wonderfully well. It may be something else but it no longer dies, plus when I used a 1uf capacitor it would cut off even sooner than a 100uf. Whatever, it works and I'm happy. Now onto my patch panel Soubdlab.

Here's a pic of the end result. It's painted with Rustoleum Hammered Finish. Looks even better in person. Very texturalized.

You do know that cap is polarised right?
I just thought that if you put it in the wrong way around then it would slowly decay it's dielectric and end up shorting the battery. I think.
It might be something else, but I always reckon it's best to check the most obvious possibilities first._________________What makes a space ours, is what we put there, and what we do there.

Ceramic caps are not polarised. Neither are MKT, Greencaps, Polystyrene, Mylar and Monolithic.
Standard Electrolytic and Tantalums are polarised. You can also get Bi-Polar or Non-Polarised Electrolytics which aren't.
I don't think you'll find a multi-layer ceramic @ 100uF though. I'm pretty sure they are like normal ceramics (yet more accurate/stable) and only go to around the 10-50nF values.

Sorry, I just checked that out, and it seems multi-layer ceramic with leads go up to 1uF.
And the multi-layer ceramic SMDs do go up to 100uF and beyond, I'm not 100% sure whether they are polarised or not, but I think they are, as all the photos I saw have a red dot on one end.

I've built a pair of WSGs and on one I had a similar issue to the one described above - with mine it doesn't fade to silence but it goes quiet and sounds like the filter is half closed. Again bypassing or shorting the capacitor at C7 seems to make it work fine; it's in the right way round and I can't see anything else obviously wrong with it. Strange, though it's still usable. The other one works fine - a wonderful little noise box.

I've had this problem too but was waiting to experiment a bit more before confirming that things were WRONG. Yes I'd figured it was the filter 'cos I tapped the direct pre-filter WWZ output and that worked just fine.

So, have we any idea why this could be happening? It is strange that you, discointellect, had it occur on only one of your circuits... VERY STRANGE.

Ah, by the way, I also tried out Low Power Modding - the 40106 behaves in really wondrous ways if you starve it of power, but the filter circuit really needs full power always, so I cut the trace that goes to the 40106 power pin (14) and inserted a 1M log pot in series. This works REALLY well. Try it Try it Try it!_________________http://www.bugbrand.co.ukhttp://www.bugbrand.blogspot.com

I'm glad people are having fun with the WSG. Seeing everyone's cases and projects is awesome. Here's some explanation on the filter. I'm not certain why it would be acting strangely but here's the scoop. The LM741 expects plus and minus supply voltage. Since the WSG only uses one nine volt battery we have to fake out the LM741 by creating a virtual ground half way between 0V and 9V. R20 and R21 form a voltage divider so that 1/2 the 9V supply appears on the positive pole of electrolytic cap C7. C7 being 100uF lowers the impedance of our virtual ground (which is what we want). Your DVM should show half the supply voltage between the + side of C7 and ground. Applying this voltage to pin 3 of U2 allows it to operate on a single supply (the op amp thinks its on a +/-4.5 volt supply because of the pin 3 biasing). It is very important that C1 be in the circuit because we only want to permit the AC content of the signal to be applied to R13 (the filter input resistor). Also R10 must be connected to the junction of R20, R21 and C7 because the filter is controlled by bringing the junction of C1 and C3 either closer to (higher cutoff frequency) or further from (lower cutoff frequency) the virtual ground point. One last point that is important is this. On the schematic wires may cross one another and not indicate connection. Connections are always indicated by dots at wire junctions. I'll throw my WSG back on a breadboard and triple-check but the filter worked as shown when I made it and I'm pretty anal about documentation. One last last thing. If you have chosen another general purpose op amp that is designed to be used on a single supply that may affect your outcome.

Yeah, that's exactly as I imagined it'd be.. BUT, I just realised I used a 1u instead of 0.1u cap for C1 - now, that could potentially allow DC through and foul things up... That really is the only difference I can see.. I'll post back with what I find._________________http://www.bugbrand.co.ukhttp://www.bugbrand.blogspot.com

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